g4beamline study of Si PIN diodeBill Ashmanskas

2008-03-06

I didn't start until I got Camille's reminder email

yesterday ...

Nevertheless, I got something useful out of the

simulation!

So g4beamline is a pretty handy tool

Mean E is 4 keV out of 660 keV. But in fact only 1% interact at all, and the ones that

do interact seem to lose most of their energy. (Note that I measured energy lost by photon,

not necessarily energy gained by silicon.) Not sure why a handful of E > 660 keV.

preview of punchline

... stop here if you're bored

just google “g4beamline”

simple ASCII description of problem to be simulated

run the program ...

check that geometry is not crazy (1000 evts shown here)

Ran 100K tracks in 2 minutes on a 6 year old

PC (1.8 GHz P4)

I chose ASCII output; you could choose ntuple, root, etc.

note that this is the output of a test run (1000 tracks), not the final run

match upstream & downstream particles; output consolidated data (e.g. E in keV)

Mean E is 4 keV out of 660 keV. But in fact only 1% interact at all, and the ones that

do interact seem to lose most of their energy. (Note that I measured energy lost by photon,

not necessarily energy gained by silicon.) Not sure why a handful of E > 660 keV.

660 keV photons from Cs137 source

S1223-01 Hamamatsu silicon PIN diode

From datasheet:

Window 5.9mm, 1.3mm thick, borosilicate glass

Effective active area 3.6mm x 3.6mm

Egap 1.12eV at 25°C

From elsewhere

316.5m intrinsic region thickness